The present invention relates to positioners for automatically repositioning cases which have been deposited on a conveyor in an improper orientation. In the dairy industry, it is common to transport cartons of milk from the dairy to customers in cases formed of plastic, wire or the like. These cases are of various sizes, such as 13".times.13", 13".times.16", and have four rectangular side walls and a rectangular bottom with an open top.
In a typical dairy installation, these cases are returned to the dairy, are stacked into vertical stacks, and are fed to a unit called an unstacker. The unstacker feeds the cases one stack at a time to an elevated, horizontal conveyor called the run-off section. From this section, the cases are fed to a second horizontal conveyor and are inverted as they are deposited onto the conveyor. The overhead conveyor is usually positioned approximately eight feet above the floor and is effective to transfer the inverted cases to a washer or other piece of equipment.
In normal operation, the unstacker is effective to properly invert the vast majority of cases. However, in most dairies a number of cases, for example, ten a day, are not properly positioned on the conveyor with their open top facing downwardly, but rather are left upended, i.e., in a position in which the case is standing on one end with its open top facing forwardly. In the past, it has been necessary to have a workman straighten out the resulting jam which is caused by one of these upended cases. When a jam occurs, it results in a shutdown of the case-loading equipment for a period of from three to four minutes.
In the past, in other fields there have been proposed various mechanisms for reorienting, or inverting, various articles, such as lids, plates, boards, caps or the like. Typical mechanisms are shown in U.S. Pat. Nos. 1,945,888; 3,275,122; 3,863,757; 3,993,187 and 4,484,675. However, none of these mechanisms was either intended to, or capable of, automatically repositioning upended cases of the type described.